On Wed, 2020-05-06 at 09:08 -0300, Adhemerval Zanella via Gcc wrote: > > On 30/04/2020 18:12, Jakub Jelinek wrote: > > On Thu, Apr 30, 2020 at 05:37:26PM -0300, Adhemerval Zanella via Gcc wrote: > > > Hi all, I would like to check if someone could help me figure out > > > an issue I am chasing on a libgomp patch intended to partially > > > address the issue described at BZ#79784. > > > > > > I have identified that one of the bottlenecks is the global barrier > > > used on both thread pool and team which causes a lof of cache ping-pong > > > in high-core count machines. And it seems not be an aarch64 specific > > > issue as hinted by the bugzilla. > > > > This has been a topic of GSoC last year, but the student didn't deliver it > > in usable form and disappeared. > > See e.g. thread with "Work-stealing task scheduling" in subject from > > last year on gcc-patches and other mails on the topic. > > In my understanding what I am working is not exactly related to OMP tasking, > although I see that the global barrier is still an issue on omp task > scheduling. > What I am trying to optimize in this specific case is the barrier used > on gomp_thread_pool used on constructs like parallel for and maybe a > per-thread > barrier could be extended to other libgomp places. > > > So if you'd have time and motivation to do it properly, it would be greatly > > appreciated. > >
Hi, Sorry for the disappearance, I've been working on my thesis. I'll come back to the work-stealing scheduler soon. Sorry for the inconvenience. Ray Kim
